Arduino Nano UnderSheild Instructions
Hooray! You got yourself a Nano Undershield! Yup, this is simply a great robot-brain/motordriver combo for small, simple robots.
The assembly instructions for both the Classic and the Undershield with Pins can be found here at Instructables.
D3 Direction Pin Motor A
D4 Direction Pin Motor A
D5 PWM Pin Motor A
D6 PWM Pin Motor B
D7 Direction Pin Motor B
D8 Direction Pin Motor B
D10 General Use Digital (Ping, SRF05, etc.)
D11 Servo 1 (Signal wire has 4.7k resistor)
D12 Servo 2 (Signal wire has 4.7k resistor)
A6 ADC 1
A7 ADC 2
**Note: On version 1 boards, the ADC pins were mislabeled during production. The ADC labels are in reverse order along the side of the board and also the end connections. I.e. The pins labeled A0 is actually A7 and the pin labeled A1 is A6. This does not affect the functionality of the board in any way.
There are 4 pins together on the side of the board allowing you to run external power to the 3-pin headers and/or connect power to the Arduino Nano, bypassing the on-board regulator.
With the jumper in this position, power from the on-board voltage regulator (From the Nano) will power the row of 3-pin headers with 5v. Care should be taken to not suck too much juice from this little volt reg. Read the datasheet for the Nano, as well as the information that came with your servos and other accessories to be sure you are good to go.
With the jumper removed, you can input external regulated power to power the 3-pin headers. In this position, external power is sent to the 3-pin headers only but NOT to the Nano itself. The Nano will still need to be powered via “Data Pwr In” from the bent headers on the other end of the board. One example for this set-up would be if you choose to use big servos --too big for the on-board regulator of the Nano itself.
With the jumper installed, and feeding the board external regulated power, you can power both the 3-pin headers and the Nano. Note: Using the board with this set up jumps over the on-board regulator of the Nano. I.e. DO NOT input power above 5v with this set up, you will smoke your Nano. This set-up is also handy if you want to use a smaller power source, i.e. 4.5v to power the Nano and thus, need to bypass the onboard regulator. DO NOT connect anything to the “Data Pwr In” when using the board in this position.
The Nano Undershield can be mounted via 2-56, 4-40 or M3 hardware.